Willow Creek Dam
Willow Creek
Willow Creek, located in Westport, South Dakota, is a vital water resource managed by the local government with oversight from the South Dakota Department of Agriculture and Natural Resources. The dam, constructed in 1934 by the Works Progress Administration (WPA), stands at a height of 49 feet and has a storage capacity of 7,650 acre-feet. With a drainage area of 155 square miles, the dam serves as a crucial flood control and water supply structure for the region.
The dam's spillway, with a width of 120 feet, is uncontrolled, allowing for the release of excess water during peak flow events. Willow Creek Dam is classified as having a high hazard potential, but its current condition is assessed as fair. Regular inspections are conducted every three years to ensure the dam's structural integrity and safety. Although the risk assessment indicates a moderate level of risk, the dam is equipped with vertical lift outlet gates to manage water levels effectively.
The presence of Willow Creek Dam underscores the importance of effective water resource management in mitigating flood risks and ensuring reliable water supplies for the surrounding community. Climate enthusiasts and water resource stakeholders can appreciate the dam's engineering design and the collaborative efforts involved in its operation and maintenance to safeguard the local ecosystem and residents from potential hazards.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Willow Creek -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Elm R At Westport Sd | 104 cfs | → |
| Foot Creek Near Aberdeen | 67 cfs | → |
| James R At Columbia Sd | 79 cfs | → |
| Maple R At Nd-Sd State Line | 62 cfs | → |
| James River At Nd-Sd State Line | 259 cfs | → |
| James R Near Stratford Sd | 453 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Willow Creek.
Boat launches
See all →
About Willow Creek
Where does the data for Willow Creek come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the High hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card below for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.